tree fde11fbe9f87e95ef6078fcbfed5f55c9ba134f8
parent cbdf35bcb833bfd00f0925d7a9a33a21f41ea582
author Miklos Szeredi <mszeredi@suse.cz> 1414102476 +0200
committer Miklos Szeredi <mszeredi@suse.cz> 1414102476 +0200

vfs: add whiteout support

Whiteout isn't actually a new file type, but is represented as a char
device (Linus's idea) with 0/0 device number.

This has several advantages compared to introducing a new whiteout file
type:

 - no userspace API changes (e.g. trivial to make backups of upper layer
   filesystem, without losing whiteouts)

 - no fs image format changes (you can boot an old kernel/fsck without
   whiteout support and things won't break)

 - implementation is trivial

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>